Semiconductors devices such as memory devices reside in many computer and electronic products. Memory devices store data.
Most memory devices have data terminals for transferring data and strobe terminals for transferring strobe signals. The data is transferred based on timing derived from the strobe signals.
The data usually includes many data bits. A strobe signal typically has specified timing windows or data valid windows for transferring the data bits. Each data bit is transferred within a data valid window. The accuracy of a data bit is unpredictable when the data bit is transferred outside the data valid window.
Some memory devices are designed to transfer data at a higher data rate. In these memory devices, the timing for the data valid window is usually smaller than that of the memory devices with a lower data rate. When the data valid window gets smaller, keeping data bits within the data valid windows become harder. Thus, in some memory devices, the accuracy of the data decreases at a higher data transfer rate. In some cases, the decrease in accuracy of the data may lead to invalid data.